Old-time FORTRAN programmers (like me) were taught (at least in early
days) that division cost a lot more machine cycles than multiplication.
So, if you had an expression like y = x/c that was going to be called
many times inside a loop, where x and y were variables and c a constant,
you'd code this as:
(Outside the loop)
cInverse = 1/c;
(Begin loop structure)
y = cInverse * x
Does this still make any sense in Mathematica? Or is it a primitive
relic of long-gone days?